A conventional heart rate monitor assembly generally includes a flexible belt, a measuring device and a display unit. The flexible belt is arranged to the user's chest and the measuring device is located at the position where the user's heart is located so as to detect the user's heartbeat. The measured information can be disclosed on the display unit. Usually, the measuring device is composed of a data processing unit and conductive plates, once either one of the data processing unit or the conductive plate needs to be replaced with a new one, the whole measuring device has to be discarded.
The present invention intends to provide a heart rate monitor assembly wherein the measuring device includes a date processor and two conductive plates and the belt has two connection ends which are easily connected to a case so as to be in contact with the conductive plates to provide electric power to the data processor.